1. Field of the Invention
The present invention relates to a semiconductor wafer treatment method. More particularly, the present invention relates to a treatment method for rectifying a deviation within a semiconductor wafer generated from a process.
2. Description of Related Art
With the current semiconductor manufacturing technology, multiple process steps are involved in the manufacturing of a semiconductor device, ranging from the manufacturing of semiconductor wafer materials to the packaging of the semiconductor device. Further, each process step affects profoundly the critical dimension and the specification of the semiconductor device. Therefore, the process parameters in each process step are carefully adjusted to effectively control the quality of the product.
Advanced process control (APC) is an essential methodology used in maintaining and controlling critical processes during the fabrication of integrated circuits. In a semiconductor process, an individual or an integrated calculating tool is applied to achieve the wafer-to-wafer or run-to-run advanced process control. A wafer-to-wafer advanced process control basically includes performing a calculation according to the information obtained from a wafer subsequent to a treatment, and feeding-back the calculated result to a process for a next wafer. The run-to-run process control, on the other hand, includes integrating information of the process equipment and of the manufacturing process and variables of the process status and of the wafer quality control, estimating through process modeling, and feeding-back on-line to adjust the process parameters.
Whether a wafer-to-wafer or a run-to-run advanced process control method is applied, a feed-back process is used to adjust a subsequent wafer process. However, the critical dimensions of different parts of a wafer vary after a process is performed on the wafer. For example, the critical dimension at the central region of the wafer deviates from the critical dimension at the peripheral of the wafer. When a subsequent process is performed on the wafer, the deviation between the central region and the peripheral region of the wafer becomes more prominent. As a result, the characteristic of the semiconductor wafer is inconsistent. Since the conventional advanced process control is only directed to wafer-to-wafer or run-to-run process control, a localized compensation within a wafer is not provided. Therefore, any the deviation in the critical dimensions or other critical control variables within a wafer can not be resolved.